This invention relates generally to broadcasting systems, and specifically to a system for transmitting data associated with audio or video program material to provide a listener or viewer with useful information regarding the program material.
Many radio broadcast systems are known to exist in which digital data are transmitted along with audio program material. For example, the United States Radio Broadcast Data System ("RBDS") Standard, published by the National Radio Systems Committee and sponsored by the Electronics Industry Association and the National Association of Broadcasters, describes a system for broadcasting a variety of program-related information on a subcarrier of a standard FM broadcast channel. The RBDS standard teaches a system for transmitting station identification and location information, as well as time, traffic and miscellaneous other information.
U.S. Pat. No. 5,063,610 to Alwadish discloses a system in which advertising text, song titles, or other program-related data may be transmitted along with audio program material and stored, displayed, or printed by a listener using appropriate receiving apparatus. The Alwadish system is understood to require data corresponding to program material to be stored along with the program material source itself (i.e., on compact disc or digital audio tape). Thus, the Alwadish system relies on customized audio program source hardware and software.
In another field of art, several systems have been taught for automatically monitoring received broadcast signals in order to log the program content of such broadcasts. For instance, U.S. Pat. Nos. 4,450,531 and 4,843,562 to Kenyon et al. teach schemes for automatically recognizing received program material as one of a number of "reference" library programs.
Notably absent from the known prior art, however, is a system for broadcasting program material and associated data that does not rely on customized program source material and related apparatus in which the program and the data are linked at the program source level. It would be desirable to have a system in which conventional program sources (e.g., conventional phonograph records, tape cartridges, or compact discs) could be played using conventional program source apparatus (e.g., conventional turntables, tape cartridge players and compact disc players), yet still provide the advantages of transmitting data pertaining to the program material.